Some rounds might be finished by then, so a combination of playoff finish and regular season standings is probably best.

Yeah, basically whatever we know for sure by Apr. 27th should be what we use, I guess. Which means any eliminated teams would have their spot in the order finalized, but the remaining teams would probably have to be re-ordered according to regular season standings for the remaining picks. That includes series(') in progress during rounds that have already had eliminations, I suppose.

Not hard to edit the order in the OP, and by the time it matters, everyone affected will have had more than enough time to find out.